The present invention pertains to a preservative composition for wood and wood building materials, and more especially, to such a preservative composition based upon an organic, preferably an oily or oil-type solvent material and one or more organic insecticides and/or fungicides and/or wood-preserving organic chemical compounds which are soluble in the solvent. The invention particularly concerns wood preservatives having a marking effect, and the invention further pertains to a process for the preparation of such marking and/or marked wood preservatives as well as to a method for using such preservatives.
It is already known to mark oily and oil-like wood preservative compositions with oil-soluble cadmium compounds, particularly to provide qualitative detection and to determine the amount of preservative in the wood (see German Pat. No. 1,080,327). For this purpose there are used as oil soluble cadmium compounds the salts of acids present in tall oil or salts of naphthenic acids. The additive component must be utilized in amounts of approximately 0.05% by weight. Based upon hygienic reasons, however, as a result of their toxicity, cadmium compounds should no longer be contained in oily wood preservative compositions. In addition, cadmium compounds are not universally usable in mineral oil-containing wood preservative compositions. They are soluble only in hydrophilic solvents, which can be used not at all or only in small amounts for wood preservative compositions.
Consideration has also been given to marking the preservative composition with weakly radioactive substances, although such a solution appears objectionable based on hygienic considerations as a result of the only difficultly ascertainable, possible danger to people or animals, especially in the case of unforeseeable accumulation of the marking material.
Attempts have also been made to use fluorescing compounds, such as pyrene and fluoranthene as marking substances in oily compositions. In the periodical "Der praktische Schaedlingsbekaempher", from January 1974, pages 1-4 (Vol. 26), a report about a new process for analyzing oily wood preserving materials with the use of fluorescing compounds as the marking substance is presented by Dr.-Ing. H.-J. Petrowitz and Ing. grad. W. Berghoff. According to this analysis method, however, approximately 2% pyrene or fluoranthene are required in the composition, in order to enable determination of the amount of wood preservative in the wood, so that the relatively high weight amounts and the costs connected therewith place in question the practical application of this method. Moreover, these compounds are not totally without objection from the standpoint of health and/or hygiene.
Purely organic marking substances such as those mentioned hereinabove, have the disadvantage that even at room temperature a certain vapor pressure results and that, as a result of this fact, a considerable portion of the marking substance evaporates over the years.